> > Well, Norton I is acting up again. The Ladung light comes on when you > rev the engine higher. > > It hten goes off at the lowest possible idle. Once it comes on, it > remains on until you return to the lowest idle speed. > > Weird. Quite the opposite of what you'd expect. > > And the belt IS tight.
Could be the brushes are bouncing at higher speeds, due to rough or out-of-round slip ring.
Check the voltage, and if it's below 14.0, remove the alternator and check the brushes.